Pneumatic hammer



Aug. M, 1923.

, w E. vom LEESEN v PNEUMATI C HAMMER 2 Shams-Sheet 2 Filed July i1,1921 f .lweniapg cation. y

This invention relates in general to pneuvalves. Y

The invention is illustrated in the draw-V hammer,

Patented Aug. i4, i923.

* vtra sir Application filed July 11, 1921.

To aZZ whom t 'may concern:

Beit known that I, EMIL von LEESEN,

a citizen of Germany, residing at Berlin,- Germany,l have inventedcertain new and useful Improvements in Pneumatic Hammers, of which thefollowing 1s -a specifimatic-hammers, more especially to .controllingdevices or gear for hammers of this kind havmgseparate cylinders for theair Av feature of according to pump and the tup piston. the novelcontrolling device the invention is that a Vsingle valve is` used forconnecting the lower andy upper ends of thetup cylinder to the lower andupper ends of the pump cylinder or to the atmosphere. The valve used ispreferably one of the rotary type with a middle chamber arrangedk to actas a compression chamber.

By using a single valve or ,memberv for controlling the air passagesbetween the cylinders of the pump and hammer the leaks are reduced tothe utmost and consequently the power consumed is lessened. Besides, thecosts of producing the machine are diminished and its reliability ofoperation is enhanced. f

Another advantage of the invention is that with the single controllingmember or valve it ispossible to use the hammer in all the differentways, or in other words, to eXecute all the different kinds ofstrokesthat hitherto could only be attained with the aid of at leastFig. 1 is a vertical section through the Fig. 2 is a longitudinalsection through the guide bushing of the rotary valve,

Fig. tis a view of avalve with auxiliary'backpressure valve,

' Fig. 4 is a view of a valve with tWo'internal auxiliary back pressurevalves,

Fig. 5 lis a cross section of the rotary valve and the 'passages orports controlled thereby taken on the line 5-5 of'Fig. 2,

.Fig `6'is a'l cross section of the valve'and ports 'taken on the line6-6 of Fig. 2,

Fig. .7 is a cross section of the valve,V and ports on the'line 7e? ofFig.' 2, i Y

Fig. 8 is a section ot the cylinders and the valve on the line 8'-8 ofFig. l0,

Vnected to the two end Vltwo main'valves and auxiliary an intern alliandle r, or by a foot .the connecting rods t,

nitraat cri-sica.

. EMIL von LEEsEN, 0E BERLIN, GERMANY.

PNEUMATICI HAMMER.

Serial No. 483,928.

Fig. 9 is a longitudinal section of the valve on the line 9-9 of Fig. 8and Fig. l0 is an elevation of a pneumatic hammer. Y

Fig. ll is a vsection on the line ll-ll, Fig. 9.

Fig. vl2 is a section on the line l2-l2, Fig. 9.

The rotary valve a, (Figs. l to 7) which is common to the upper andlower cylinder spaces, has two mainV ports and c. Through the passages fand g the port establishes-connections between the cylinder spacebeneath the under side Z of pump piston and the cylinder space beneaththe under side c of the piston connected to the tup, and through thepassages 7c and Z the port c establishes connections between the upperspace of the cylinder of the pump and the upper space z' oit' the tuppiston cylnder. The main ports o and c, as shown in F 3, arerespectively arranged near opposite ends of the rotary valve. The middleportion of the valve a has av hollow space or chamber m which is eitherconnected to an end port Z) by a single back pressure valve a that opensfrom rto m as shown in Fig. 3, or which, as shown in Fig. 4C, may beconports Z) and c by two back pressure valves n and 0 that open into m.The said chamber m has a lateral port p which, `according to theposition of the valve o, establishes a connection from the chamber meither to the lower space c of the tup piston cylinder vthrough thepassage f, or to the upper space a' of this cylinder through the passage70. The bushing surrounding the rotary valve c, `and :firmly pressedinto the frame ot the hammer, isf

only provided for the purpose of enabling the 'inlets into the variouspassages 7, g etc.

spaces formed by cores body of the hammer.

The valve a is controlled either by the lever s acting through The modeof operation of a hammer conwhen casting the Jrrolled in this way willbe understood from Figs. l, 5,V 6 and 7. Fig.v 5 is a vertical sectionthrough the port Z; of the rotary valve andthe adjoining passages fandg, Fig. 6 a vertical section through the middle chamber m ot the valveand the adjoining passages f and 7^., and Fig. 7 a vertical sectionthrough the port 0 oit the valve and the adjoiningl passages 7c and Z.

Zhen the rotary valve is in the position shown in Figs. 57 (3 and i' thetup is kept suspended in its highest position. Since the passage f (Fig.leading tothe lower tup cylinder' space is closed. the lower side (Z oiltie pump piston will press air through the back pressure valve uinto'the pressure chamber m (Fi (i) and thence through the openingpzintothe passage and the lower tup cylinder space c (Fig. l) thus driving`the tup piston upward. At the same time the upper tup cylinder space Zwill be connected through the passage Z: (Fig. 7), a notch a: in thevalve c, and an outlet y to the atmosphere, so that 'for a while no resistance will be ofl'erel to the tup piston w by themedium in the spaceabove it. lint shortly betore the tup piston reaches its topmostposition its upper edge closes the mouth oi' the passage 7c leading intothe; cylinder so that an air cushion is formed which resists the furtherupward movement ot the tup piston. l

Iii the rotary valve is `now turned by: means ot the handle r or 'thepedal s in the direction indicated by theV arrows a direct connectionthrough the port Z) oiE the yalve a (Fig. 5) will iirst be establishedbetween' the pump cylinder space (Z and the lower tup cylinder space c,this connection includinal the `'passe-ges .g and' The suctional andpressure etl'ects produced in the lower space of the pump cylinder willcauseV the tup to execute gentle up' and down strokes so that verygentle blows of the tup will result.

It the rotaryyalve is turned further around in the direction of thearrows a direct con nection through the port c (Fig. 7) will also beestablished between the top space l-l.

` ot theY pump cylinder' and the topV space i oit` the Vtopcylinder riathe passages Zt and Z and-consequently the `blows ot the tup willgradually become more Violent. v

Zhen the rotary valve is turned completely round the passages betweenthe channels f and; gpand 7c and Z, lea ding through Z)A and crespectively, widest extent. i. e. the connections between the upperandlower cylinder spaces willlbe most ethcient7 vsothat the tupnwillexecute its most violent blows.

ltthe pedal Sor the handle 11 is Vnow rcleased theyalre (L will beimmediately restored by the weight Q attac-hed to the lercr Y t to theposition in which it causes the tup to .be raised and topmost positionin which. suspended.V f A It desired the tup may be lowered onto thework. and :caused to remain thereon whilst eiierting (-,onstan'tpressure.

end the handle r is turned in the `direction opposite to that indicatedby the arrows.V

tlievtup will fly into its' it will be kept The cross section ot thevalve a. orv the will be opened to their y is, a Vchamber E To this1When turned in this position the connection between the port Z) of thevalve a (Fig. a)V and the lower tup cylinder space e is cut oil. Thelower space EZ of the pump cylinder co operates through the backpressure valve n with the pressure space m whose port p registers withthe passage Z; leading to the upper tup cylinder' space t' so piston isforced down by compressed air from abore. At the same time the Vlowertup cylinder space c will .be connected through the passage f, (Fig. l?in therotary valve and the port H to the atmosphere, and the connectionextending i'roin the .passagethrough the notch rotola the port y/ (Fig.7,), which leads into theatmosphere will be closed. On the other handthe upperspace L of the pump cylinder will still be connected to theatmosphere through the notch@ and theports Z and y. l

Finally7 it the tup is to be caused to execute single strokes at anydesired speed independently of thenumber ot strokes carthat the tupV o),the notch Y ried out by the pump it is only necessary to shift thehandle r to and iiro at the desired speed trom the Vposition in which itcauses the tup to be lowered, and kept constantly pressing down on thework. into the position in which it causes the tup to be kept suspendedin its topmost position. Y

Fig. lshows a modification o'l' the rotary valve for hammers for swagingwork. When this 'lorm of Valve is turuedinto the position in which itcauses the tup .to remain suspeiuled in its topmost position,A or inwhich itcauses the tup to constantlyrpress down on the work, the upperpump cylinder spaces are both connected through the two back pressureyalyes u and 0` to the pressure chambcrjm, and a higher and more uniformpressureis thus obtained. line (,.Fiez 2 is then .made Vsin'iilar inshapelo the section on the line 5-5, Fig. 2 and the notch l) in theexteriorotthe rotary yalre is omitted. V

in the modiiicatiou 9 thev rotary Valve is subdivided and the individualparts are arranged to be adjusted` withrespectto eachother.

The interior of the one halt R of the with ports adaptedto eilectconnections between the, lower.spa'ces'oic the cylinders. ,The otherhaltY ot the valve AS comprises a chamber S with ports adapted Vtoeitectconnections between theA upper spaces oit the cylinders. Betweenthe two alres l` and S ot the Valve which are arranged 1n a common borethere 1s a pressure chamber M adapted to be lilled with air that passesin from the chambers R and S through the back pressure yalves N and O.The compressed air from the pressure space M may beconducted through achannel Z in the valve member Vld into'the air and lower yalre shown inFigsB 'and passage F and the lower space E in the tup cylinder. By ,thismeans the tup is kept in its topmostV position.;

.By turning the valve in a suitable mannerA a similar channel in thevalye member ,SV is brought into a position in whichcompressed airpassesfrom the pressure chamberjM through the air .passage 7c into the topspace in the tup cylinder. By this means the tup iscaused to presssteadily down.contov the anvil. By arrangingthe one half ot' the valveon a cone K ofthe common shaft L and the other halt S on an elastic keym the two said valves are made adjustable with respect to each other.

The elastic connection by means'of the shaft obviates the possibility ofthe valves becoming stuck in the bore through unequal heating which isvery liable to occur in the case of valves accurately fitted into theirholesby grinding.

I claim l. In a pneumatic hammer, a tup piston, a pump piston, separatecylinders Jfor the said pistons, primary passagesfor interconnecting thecylinder spaces above the said pistons, secondary passages forinterconnecting the cylinder spaces beneath the said pistons, a port forconnecting the tup cylinder to the atmosphere; a single oscillatoryvalve controlling all of the said passages and the said port; means foroperating said valve, and means whereby when the valve operating meansis released the valve is positioned to elevate the tup piston.

2. In a Apneumatic hammer, a tup piston, a pump piston, separatecylinders for the said pistons, primary passages for interconnecting thecylinder spaces above the said pistons, secondary passages forinterconnecting the cylinder spaces beneath the said pistons, a port forconnecting the tup cylinder to the atmosphere; a single rotary valvewith ports at its two ends and a chamber at its middle portion, the saidrotary valve being adapted to control all of the said passages and thesaid port,V means for operating said valve, and means whereby when thevalve operating means is released the valve is positioned to elevate thetup piston.

3. In a pneumatic hammer, a tup piston, a pump piston, separatecylinders Jfor the said pistons, primary passages for interconnectingthe cylinder spaces above the said pistons, secondary passages Jforintercorring the cylinder spaces beneath the said pistons, a port forconnecting the tup cylinder to thel atmosphere; a single rotary valvehaving ports at its two ends, a pressure chamber at its middle portion,and a back pressure valve between one of its ports and its pressurechamber, said rotary valve being adapted to control all of the saidpassages and the said port; means for operating said valve, and meanswhereby whenthe' valve operating means is released the valve ispositioned to elevate the tup piston.

l 4V. In a pneumatic hammer,a tup piston, arpump piston, separatecylinders for the said pistons, primary passages for interconnecting thecylinder spaces above the said vpistons, secondary passages forinterconnectingthe cylinder spaces beneath the said pistons,a .port forconnecting the tupcylinder to the atmosphere; anda single rotary valvecomprising, two port chambers which are adjustable with respect to eachother, the valve being adapted to control the said passages and the saidport.

5. In a pneumatic hammer, a tup piston, a pump piston, separatecylinders for the said pistons, primary passages for interconnecting thecylinder spaces above the said pistons, secondary passagesforinterconnecting the cylinder spaces beneath the said pistons, a portfor connecting the tup cylinder to the atmosphere; and a single rotaryvalve comprising, two port chambers, a common shaft connecting the twochambers, the two charnbers being adjustable with respect to each other,and the one chamber cooperating with the upper cylinder spaces, whilstthe other cooperates with the lower cylinder spaces, the said valvebeing adapted to control the said passages and the said port.

6. In a pneumatic hammer, a frame, a

tup piston, a pump piston, separate cylinders for the said pistons,primary passages for interconnecting the cylinder spaces above the saidpistons, secondary passages for interconnecting the cylinder spacesbeneath the said pistons, a port for connecting the tup cylinder to theatmosphere, a bore in the said frame; and a single rotary valve arrangedin the said bore and comprising, two port chambers, a common shaft forthe two port chambers, these chambers being mounted on the shaft in thesaid bore at a distance from each other so that a middle chamber isformed in the said bore, ring-shaped back pressure valves for connectingthe port chambers with the said middle chamber, the one back pressurevalve cooperating with the said primary passages, whereby the tup pistonis lowered, and the other back pressure valve cooperating with the saidsecondary passages, whereby the tup piston is raised.

7 In a pneumatic hammer, a frame, a tup piston, a pump piston, separatecylinders for the said pistons, primary passages for interconnecting thecylinder spaces above the said pistons, secondary passages forinterconnecting the cylinder spaces beneath the said pistons, aV portfor connecting the tup cylinder to the atmosphere, a bore in the saidframe; and a single rotary valve -arranged in the said bore andcomprising, two port chambers, a common shaft for the two port chambers,the shaft having a conical portion at the middle and two threadedportions near its ends, a nut on onel ofthe Asaid threaded portions forfixing one'of the said port cliainberson the said conica-1 portion, a

second nut and a key on the common shaft for fixing the other portGhamber, both Chambers `being mounted on the shaftin the said bore at adistance from each other so that a middle chamber is lg'ormed in thesaid bore, ring-shaped back pressure valves for connecting the portoha'nibers with the said Vthe said secondary passages, whereby thetuppiston is raised. 4

In testimony whereof lV have signed this vspecification in the presenceof t-Wo Witnesses.

Y. Y EMIL vVoir LEESEN, Witnesses:

RICHARD JARVIES, GERTRUD Mn'wns.

